According to geimin.net, PS3's LTD at the end of 2007 (the year Gundam Musou was released) was 1,641,671, and it's close to WiiU's current LTD at 1,871,750. While the latter may be true, PS3 was also way more expensive than WiiU, so I think it's a fair comparison.
That's right, I wasn't paying attention, I was thinking more about the Dynasty Warriors as a whole. One could argue that Musou fans were among the firsts to get a PS3, as the first week sales for the Musou games didn't increase as much as the install base. DW 8 sold 203k at launch on 9 mio. install base.